August 14, 2003

Global Warming is Choking the Life Out of Lake Tanganyika

Let's take stock of our situation...The real war on
terrorism is being lost while the Ashcroft Just Us
Dept. concocts penny-anty arms merchant stings for "US
mainstream media" consumption, the Homeland
Insecurity Dept. doodles with its Crayola crayon
"Alert system," and US military and intelligence
resources are squandered in the quagmire of Iraq
(where is Osama bin Laden?). The real Middle East
peace process was allowed to languish and die through
the _resident's policy of "malign neglect" only to be
replaced by a roadmap to oblivion half-heartedly
promoted by a foolish little man who cannot
distinguish the West Bank from the East Bank. The
_resident's economic quackery has led to the gutting
of the US budget surplus and the tanking of the US
economy (where is Ken Lay?)...AND, just as Nero
fiddled while Rome burned, the _resident struts around
Waco on his "vacation," posturing for the 2004
"election," while the planet itself begins to
burn...Read the news from Europe (the Alps are
metling) and people are dying in Paris...Consider the
implications of this powerful and disturbing story on
Lake Tanganyika from the UK...

Published on Thursday, August 14, 2003 by the
Global Warming is Choking the Life Out of Lake Tanganyika
by Steve Connor

Lake Tanganyika in central Africa - where Henry
Stanley delivered his immortal question, "Dr
Livingstone, I presume?" - is in ecological crisis as
a result of global warming.

Studies by two independent teams of scientists have
found local temperature rises and climate change have
dramatically altered the delicate nutrient balance of
the lake, Africa's second largest body of fresh water.

This NASA satellite file image shows Lake Tanganyika
in East Africa. Global warming is wrecking Africa's
Lake Tanganyika, inflicting a catastrophic decline in
fish catches, a study says. They have discovered that
the surface of the lake is getting warmer and that has
meant the mixing of vital nutrients in the lake has
diminished and cut the lake's fish population.

The effect has had a dramatic impact on the local
economy, with fishing yields plummeting by a third or
more over the past 30 years and further decreases

Lake Tanganyika has traditionally supplied between 25
and 40 per cent of the protein needs of the local
people, citizens of the four countries bordering the
lake, Burundi, Tanzania, Zambia and the Democratic
Republic of Congo.

As a tropical lake accustomed to high year-round
temperatures, Tanganyika was not obviously vulnerable
to the effects of global warming yet this is what the
scientists have discovered.

All deep freshwater lakes rely on nutrients in the
lower depths periodically coming to the surface where
aquatic plants and algae live. This is particularly
critical in tropical lakes which have steep
temperature gradients that tend to keep the warm, less
dense layers on top of the colder, denser water in the
lake's depths where the nutrients are stored.

Lake Tanganikya is the second-deepest lake in the
world and the second richest in terms of biological
diversity; it has 350 species of fish with new ones
being discovered regularly. Nutrient mixing has been
vital for its biodiversity.

Piet Verburg, of the University of Waterloo, in
Canada, and Catherine O'Reilly of the University of
Arizona, in Tucson, who led the studies, found warmer
temperatures and less windy weather in the region is
starving the lake's life of essential salts that
contain nitrogen and sulphur.

Dr O'Reilly's study, in the journal Nature, suggests
the lake's productivity, measured by the amount of
photosynthesis its plant life has done, has diminished
by 20 per cent, which could easily account for the 30
per decrease in fish yields.

The scientists say climate change rather than
overfishing is largely responsible for the collapse in
Tanganyika's fish stocks and the position is likely to
get much worse.

"The human implications of such subtle, but
progressive, environmental changes are potentially
dire in this densely populated region of the world,
where large lakes are essential natural resources for
regional economies," the scientists say. Dirk
Verschuren, a freshwater biologist at Ghent University
in Belgium, said both studies could explain why
sardine fishing has declined by between 30 and 50 per
cent since the late 1970s.

"Since overexploitation is at most a local problem on
some fishing grounds, the principal cause of this
decline has remained unknown," Dr Verschuren writes in
an accompanying Nature article. "Taken together ...
the data in the two papers provide strong evidence
that the effect of global climate change on regional
temperature has had a greater impact on Lake
Tanganyika than have local human activities. Their
combined evidence covers all the important links in
the chain of cause and effect between climate warming
and the declining fishery."

2003 Independent Digital (UK) Ltd


Posted by richard at August 14, 2003 11:57 AM